Roll-fed labelling apparatus

ABSTRACT

Roll-fed labelling apparatus includes a rotary cutting drum ( 7 ) which incorporates a plurality of cutting assemblies ( 9 ) to cut a label web ( 4 ) before delivering individual labels to respective containers or bottles ( 14 ). The apparatus provides for the label web ( 4 ) to be delivered to the cutting drum ( 7 ) at a negligible tension, mitigating label stretch.

[0001] This invention relates particularly to roll-fed labellingapparatus as may be used for applying labels taken from a label web to avariety of articles. Such articles are often containers found inproduction, packaging and bottling of drinks, foods, household products,toiletries, oils, paints and the like and manufacture of plastic, glass,metal and other containers.

[0002] In conventional roll-fed labelling apparatus a label web is takenfrom a label roll stand and delivered via label feed and tensioningapparatus to a cutter drum. In order to maintain the tension in thelabel web, the cutter drum rotates at a faster velocity at itscircumference than the supplied web, requiring an immediate accelerationof the web. In practice, unless there is an appropriate degree ofslippage of the label on the drum, the label will stretch undesirably oreven tear. However, the requirement of catering for such slippage isitself problematic, imposing demanding specifications on thecoefficients of friction of the drum surface, and in respect of theregistration and glue application processes. Typically, after the web iscut into individual labels, the labels are passed on to an adjacentvacuum drum. The vacuum drum also rotates at a faster velocity than thecutter drum, and thus the aforementioned requirements relating toslippage also apply at this stage.

[0003] The labels may then be coated on their back face with anadhesive, typically at their leading and trailing edges and then passedfrom the vacuum drum to respective containers or articles brought intojuxtaposition with the label on the vacuum drum by a turret or otherconveyor.

[0004] The apparatus for applying the adhesive to the label generallyincludes a further wheel or roller having a knurled or shaped surfaceand glue wires which are positioned to prevent labels from dislodgingfrom the vacuum drum and falling into the gluing apparatus or otherequipment, causing breakage, inefficiencies and down time. These gluewires, however, have been found to be unreliable themselves, breakingfrom time to time and giving rise to the above problems.

[0005] Thus it may be seen that labelling machines conventionally haveused a series of rotating drums for the transport of labels through aseries of stages. The labels are transferred from the surface of onedrum to the surface of the next drum, and the labels are generally heldon the surface of the drum by a vacuum.

[0006] The relative speeds of the drums are critical and even a slighterror in the speed of one of the drums can lead to substantial problemsor inefficiencies. Such errors may be hard to avoid in view ofunpredictable and inconsistent levels of slippage and label stretch,causing labels to be wrinkled or creased as they are transferred fromone drum to the next.

[0007] An object of the present invention is to reduce the risk of suchwrinkling or creasing by simplifying the process required to registerand cut the label web, and thereafter apply adhesive to the labels. Inone aspect, the invention enables this by enabling more of theseprocesses to be undertaken while the label is on a single drum, therebyalso reducing the requirement of transferring labels from one drum toanother.

[0008] U.S. Pat. No. 4,632,721 Hoffmann goes some way in attempting tomeet the aforementioned objective. Hoffman teaches the use of a knifecarried directly on a vacuum drum in an attempt to negate therequirement of a separate cutter drum. However, Hoffman teaches the needfor an interaction between the vacuum drum and stationary blades whichtogether sever or shear each label from a continuous web. Glue applyingrollers are also positioned in close proximity to the vacuum drum.However, a disadvantage of the art taught by Hoffmann is that it thegripping pads, which act to hold the label to the vacuum transport drum,requires to retract and protrude at appropriate and exact times duringthe rotation of the drum in order to avoid interference with thestationary blades in one case and to cause the label to press againstthe glue rollers in another case. Thus, Hoffmann does not entirelyovercome the need to provide for precise relative speeds of onemechanism in relation to another. It is also noted in the presentinvention that the act of shearing or severing label web between amoving blade and a stationary blade is not entirely satisfactory. Thus,an object of the present invention is to mitigate these disadvantages inthe art.

[0009] Further objects of the present invention will become apparentfrom the following statements and description.

[0010] According to a first aspect of the present invention there isprovided a roll-fed labelling apparatus comprising delivery means fordelivering a label web to a rotary cutting drum, and one or more[separating] cutting means associated with the cutting drum for[separating, parting, severing or] cutting the label web into individuallabels while held by a relative negative pressure on the circumferentialsurface of the drum, the apparatus being associated with a containerdelivery means whereby containers are delivered into juxtaposition withseparated labels located on the rotary cutting drum to enable transferof the said separated labels to respective containers.

[0011] Preferably the [separating] cutting means are provided on or nearthe circumferential surface of the drum.

[0012] Preferably the [separating] cutting means comprises a sharp edgedor pointed device or instrument. The [separating] cutting means may be a[cutting] blade. Alternatively said [separating] cutting means may be aheated device or appliance, a water, ultrasonic or laser cutting device,or any device for [perforating and tearing] cutting the web intoindividual labels.

[0013] [While] Where there are a plurality of cutting blades, at eachblade there may be provided a slot in the cuter circumferential surfaceof the rotary cutting down and preferably at least part of the cuttingedge of each blade protrudes through the slot allowing contact of theblade with the label web on the cutting drum. The blade may be connectedto a piston located within a cylinder wherein movement of the piston andblade is provided by a relative change in air pressure across thepiston. Preferably, the means for providing a relative negative pressureat the outer circumferential surface of the rotary cutting drum is alsoused, when required, to provide the relative pressure change across thepiston in the cylinder. Other devices such as mechanical,electro-mechanical, pneumatic or hydraulic devices may be used in placeof the piston.

[0014] According to a second aspect of the present invention theaforesaid delivery means is such that the label web is delivered to therotary cutting drum under a low or negligible tension. The deliverymeans may comprise a free loop mechanism for this purpose.

[0015] An advantage of this is that minimal, negligible or even zeroslippage may occur in respect of the label web or individual labels onthe rotary cutting drum. Furthermore, as the label web is supplied at arelatively low or negligible tension, the label web is not caused tostretch or tear and materials of low tensile strength may be used.

[0016] According to a third aspect of the present invention the roll-fedlabelling apparatus further comprises an adhesive applicator provided inclose proximity to the rotary cutting drum to enable labels to receiveadhesive prior to their transfer to their respective containers.Preferably the adhesive applicator comprises means for spraying adhesiveonto the back faces of the labels. Preferably, the adhesives applicatorhas means for pulsing the spray such that the adhesive is ejected ontothe leading and trailing edges of the labels.

[0017] Alternatively, the adhesive applicator may be arranged to spraythe adhesive in a pattern such that the leading and trailing edges ofadjacent labels are applied with adhesive in a single action. The rotarycutting drum may be provided with an angular profile at each slot andthe adhesive applicator may also be positioned at an angle to the radiusof the cutting drum so that contamination of the slot during supply ofthe adhesive may be reduced or minimised.

[0018] An embodiment of the invention will now be described, by way ofexample only, with reference to the accompanying drawings, in which:

[0019]FIG. 1 is a schematic view of roll-fed labelling apparatus inaccordance with the invention,

[0020]FIG. 2 is a front elevation of the area marked C on the rotarycutting drum shown in FIG. 1,

[0021]FIG. 3 is a schematic plan view of example container deliverymeans used in association with the invention,

[0022]FIGS. 4 and 4b show respectively, a perspective and sectionalelevation of a cutter drum assembly, and,

[0023]FIG. 8 shows a cutter assembly used on the rotary cutting drum forcutting a label web into individual labels.

[0024] Referring firstly to FIG. 1 and FIG. 2, a label web 4 is storedon the label roll stand 2. An optional second roll stand 2 a may also beprovided to enable quick changeover of label web supply when one roll isdiminished.

[0025] From the label roll stand 2 the label web 4 is fed via deliverymeans to a rotating cutting drum 7. The delivery means includes a seriesof roller guides 30, a tension control arm 31, a label feed roller 32and pinch roller 33, and a tension negating roller 34. The tensioncontrol arm 31 is biased in the direction of arrow B so as to providetension to the label web 4 ensuring that it is pulled off the label roll2. The tension control arm 31 is pivotal about the fulcrum 35 such thatconstant and safe tension may be maintained on the label web 4 at thisstage of the delivery.

[0026] However, after the label web 4 has passed between the label feedroller 32 and pinch roller 33 it is guided around a tension negatingroller 34. The roller 34 is movable in the directions of D and E, therebeing a bias imposed on the roller 34 in the direction of D, althoughthis bias is far less than the bias on the tension controller 31, suchthat at this location a negligible tension is applied to the label web4, that is the label web 4 travels through a free loop after it passesthe roller 34.

[0027] Accordingly, the label web 4 is delivered to the rotary cuttingdrum 7 at a negligible tension and such that the face of the labels arein contact with the external circumferential surface of the rotarycutting drum 7, the backface of the labels being exposed outwardly.

[0028] Registration means 8 is associated with the rotary cutting drum 7and adapted to register the position of the leading and trailing edgesof the individual labels, ensuring that such are aligned with respectivecutters 9 on the cutting drum 7.

[0029] In use, the rotary cutting drum 7 rotates in a clockwisedirection and transports the label web 4 to the area C at which thecutter is activated by a change in relative air pressure across apiston, the details of which are described below with reference to FIG.4. To ensure a clean cutting action the relative negative air pressureis increased on the outer circumferential surface of the rotary cuttingdrum 7 in the vicinity of the label web 4 at the location of the cut(c). This may be seen from FIG. 2 which shows the elevation of the outercircumferential surface of the rotary cutting drum 7 in the area markedC in FIG. 1. The holes 50 are the outlets of conduits for sucking air orotherwise reducing air pressure in the area of the holes 50 upon thesurface of the rotary cutting drum 7. As the tension in the label web isnegligible, zero or negligible slippage of the labels occur after theyhave been cut and thus negligible spacing appears between adjacentlabels after the cutting action takes place. This means that (as shownin FIG. 2) the leading edge of a label 51 abuts the trailing edge of anadjacent label 52 at the cut line 53.

[0030] With the labels positioned in such abutment they are transportedby the rotary cutting drum 7 in a further clockwise rotation to a gluestation at which is located a glue or adhesive applicator 11. Theapplication 11 is an extrusion die and eliminates the need for guidewires. Hot melt adhesive may be applied to the front and trailing edgesof each cut label, the applicator 11 spraying the adhesive in a pulselike manner, the timing of which may be synchronised by the registrationof equipment 8. In one embodiment, the adhesive may be applied to theleading and trailing edges of adjacent labels simultaneously because thecutter drum 7 is designed to cut labels without creating any substantialgap between the separated labels. The adhesive applicator can be left onat all times for complete coverage without the need for on/off timing. Atypical arrangement of the adhesive applicator 11 is described belowwith reference to FIG 5 and 6. It should be noted of applicator oradhesive used. Indeed, the use of a glue applicator is not itselfessential and other methods may be employed for attaching labels torespective containers. Moreover, if an adhesive is to be used, theadhesive may be applied to all of the backside of the label, or onlypart thereof, such as the front and trailing edges as hereinbeforementioned.

[0031] As shown in FIG. 3, the apparatus further includes a containerdelivery means which typically comprises a conveyer 13 which deliverscontainers 14 onto a star wheel 15 via an infeed star 16. An infeedscrool (not shown) may be used in place of or in combination with theinfeed star 16. The infeed star 16 ensures that the containers arepositioned on the star wheel 16 with correct positioning such that theyare appropriately spaced apart for correspondence with delivery of thecut and glued individual labels being transferred from the rotarycutting drum 7 at a point where the star wheel 15 and rum 7 come intocontact or near contact.

[0032] The labels are wrapped around their respective containers via afixed or moving roll down pad and guide 17, after which they arereturned to a conveyor 18 by the discharge star 19. It is recognised inthe present invention that there are various methods used for deliveringcontainers 14 to roll fed labelling apparatus and the present inventionis not limited to the embodiment described herein. For example, it isenvisaged that a rotary turret in which containers 14 are clamped inupper and lower chunks may be used in place of the star wheel 15, thecontainers being rotated by means of a drive belt before coming incontact with a roll down pad and guide. As mentioned above an infeedscroll may be used in place of or in combination with the infeed star16.

[0033] Turning now to FIG. 4, a cutter drum assembly is illustratedhaving six cutter assemblies, also referred to as separating meansherein. A side view of a cutter assembly 9 in the rotary cutting drum 7is illustrated in FIG. 5.

[0034] The cutter assembly 9 in the example embodiment comprises acylinder 12 mounted on a frame 42 which drives a link 41 connected to apivotal arm 44. The arm 44 pivots about the pin 40 and provides aconnection means 25 for a blade holder 43 with cutting blade 26. Theconnection means allows for the adjustment or replacement of the bladeholder 43. Similarly, the cutting assembly may be designed to allow forthe efficient replacement of the blade 16. In use the blade 26 protrudesthrough a respective slot 53 in the cutter drum 7 to enable a cutting orseparating action to take place.

[0035] The piston 22 may be electro-mechanical pneumatic or of any othersuitable type.

[0036] It should be noted that the invention extends to any method ofseparating, parting, severing or cutting the label web whilst on thecutting drum. For example, apart from the cutting blade arrangementsdescribed above, any sharp edged or pointed devices or instruments,heated devices or appliances, water, ultrasonic or laser cuttingdevices, or devices for perforating and tearing the labels may be used.In addition, the piston described above may be replaced by any othermechanical, electro-mechanical, pneumatic or hydraulic device.

[0037] It will be realised that a significant advantage of the inventionis that it negates the requirement of a separate cutter drum. It isfound that not only does this reduce the complexity of the apparatus inorder to achieve the required function, but also diminishes thepossibility of adverse effects resulting from inexact speedcorrespondence of a plurality of rotating drums and the unsuccessfultransfer of labels from one drum to another.

[0038] Additionally, no label slippage or tensioning is required.Further modifications and improvements may be incorporated withoutdeparting from the scope of the invention herein intended.

1. Roll-fed labelling apparatus comprising delivery means for deliveringa label web to a rotary cutting drum, and one or more cutting meanslocated on the cutting drum for cutting the label web into individuallabels while the label web is held by a relative negative pressure onthe circumferential surface of the drum; characterised in that thecutting action serves to slice the web.
 2. Roll-fed labelling apparatuscomprising delivery means for delivering a label web to a rotary cuttingdrum, and one or more cutting means located on the cutting drum forcutting the label web into individual labels while the label web is heldby a relative negative pressure on the circumferential surface of thedrum; characterised in that the cutting action is not dependent upon asurface, edge or blade auxiliary to the cutting means.
 3. Roll-fedlabelling apparatus comprising delivery means for delivering a label webto a rotary cutting drum, and one or more cutting means located on thecutting drum for cutting the label web into individual labels while thelabel web is held by a relative negative pressure on the circumferentialsurface of the drum; characterised in that the cutting means comprises acutting blade or force that moves with a net relative velocity inrelation to the label web during the cutting action.
 4. Roll-fedlabelling apparatus as claimed in any one of claims 1 to 3, theapparatus being associated with a container delivery means wherebycontainers are delivered into juxtaposition with separated labelslocated on the rotary cutting drum to enable transfer of the saidseparated labels to respective containers.
 5. Roll-fed labellingapparatus as claimed in any one of the preceding claims, wherein thecutting means comprises a sharp edged or pointed device or instrument.6. Roll-fed labelling apparatus as claimed in any one of claims 1 to 4wherein the cutting means is a heated device or appliance.
 7. Roll-fedlabelling apparatus as claimed in any one of claims 1 to 4, wherein thecutting means is a laser cutting device.
 8. Roll-fed labelling apparatusas claimed in any one of claims 1 to 4, wherein the cutting means is anultrasonic device.
 9. Apparatus as claimed in any one of the precedingclaims comprising a plurality of cutting means spaced apartcircumferentially around the drum by a distance approximately equal tothe label length.
 10. Apparatus as claimed in any one of the precedingclaims, wherein the rotary cutting drum is provided with a slot for eachrespective cutting means, each slot being in the outer circumferentialsurface of the rotary cutting drum.
 11. Apparatus as claimed in claim 5,wherein the cutting means includes a blade connected to a piston locatedwithin a cylinder.
 12. Roll-fed labelling apparatus as claimed in anyone of claims 4 to 11, wherein the delivery means in use, delivers thelabel web to the cutting station under a low or negligible tension. 13.Roll-fed labelling apparatus as claimed in any one of claims 4 to 12further comprising an adhesive applicator provided in close proximity tothe rotary cutting drum to enable labels to receive adhesive prior totheir transfer to their respective containers.
 14. Apparatus as claimedin claim 13 wherein the adhesive applicator comprises means for sprayingadhesive onto the back faces of the labels.
 15. Apparatus as claimed inclaim 13 wherein the adhesive applicator has means for pulsing the spraysuch that the adhesive is ejected onto the leading and trailing edges ofthe labels.
 16. Apparatus as claimed in claim 13, wherein the adhesiveapplicator is arranged to spray the adhesive in a pattern such that theleading and trailing edges of adjacent labels are applied with adhesivein a single action.